1. Field of the Invention
The present invention relates to a ladder filter preferably use in a wireless communication device.
2. Description of the Related Art
Ladder filters have been widely used in wireless communication devices and the like.
One example ladder filter is described in Japanese Unexamined Patent Application Publication No. 5-183380. In the ladder filter, an inductance is connected in series to a parallel arm resonator. This configuration is described as being capable of increasing the attenuation outside a pass band.
However, no consideration is given to a thermal dissipation path from an elastic wave resonator in the ladder filter described in Japanese Unexamined Patent Application Publication No. 5-183380. Accordingly, there is a problem that sufficient thermal dissipation is not obtainable. Because thermal dissipation from the ladder filter is insufficient, its electric power handling capability may degrade.